#include<stdio.h>
#include<string.h>
#include<unistd.h>
int main(){
    int left = 0;
    char arr1[]="abcdef";
    char arr2[]="******";
    int right = strlen(arr1)-1;
    while (left<=right){
        arr2[left]=arr1[left];
        left++;
        arr2[right]=arr1[right];
        right--;
        printf("%s\n",arr2);
        sleep(1);

    }
    return 0;
}